The chemical reaction that occurs between [tex]NaOH[/tex] and [tex]HCl[/tex] is:
[tex]NaOH + HCl \rightarrow NaCl+H_2O[/tex]
Using formula:
[tex]M_1V_1 = M_2V_2[/tex]
where M is the concentration in molarity and V is volume of the solution.
Molarity of [tex]NaOH = 0.5 mol/L[/tex] (given)
Molarity of [tex]HCl = 2.0 mol/L[/tex] (given)
Volume of [tex]HCl = 20 mL[/tex] (given)
Since, 1 mL= 0.001 L
So, volume of [tex]HCl = 0.02 L[/tex]
The volume of [tex]NaOH[/tex] can be determined using equation:
[tex]M_{NaOH}V_{NaOH} = M_{HCl}V_{HCl}[/tex]
Substituting the values:
[tex]0.5 mol/L\times V_{NaOH} = 2.0 mol/L\times 0.02L[/tex]
[tex]V_{NaOH} = \frac{2.0 mol/L\times 0.02L}{0.5 mol/L} = 0.08 L[/tex]
Since, 1 L = 1000 mL
So, the volume of [tex]NaOH[/tex] = [tex]80 mL[/tex].
Hence, 80 mL of a 0.5 mol/L [tex]NaOH[/tex] solution required to completely react with 20 mL of a 2.0 mol/L [tex]HCl[/tex] solution.
